The effect of interhospital transfers, emergency medical services, and distance on ischemic time in a rural ST-elevation myocardial infarction system of care.

BACKGROUND: Regional myocardial infarction systems of care have been shown to improve timely access to primary percutaneous coronary intervention (PCI). However, there is a relatively sparse research on rural "frontier" regions. Arrival mode, high rates of interhospital transfers, long transport times, low population density, and mostly volunteer emergency medical services (EMS) distinguish this region from metropolitan systems of care. We sought to assess the effect of interhospital transfers, distance, and arrival mode on total ischemic times for patients with ST-elevation myocardial infarctions undergoing primary PCI. METHODS: We assessed patient data from our observational cohort of 395 patients with ST-elevation myocardial infarction with PCI as their primary treatment strategy. Data came from the 10 PCI hospitals participating in the Wyoming Mission: Lifeline program from January 2013 to September 2014. We performed both regression and tests of differences. RESULTS: Median total ischemic time was nearly 2.7 times greater in transferred patients than those presenting directly (379 vs 140 minutes). Distance in miles traveled between patient's home and PCI facility was 2.5 times larger in transfer patients (51 vs 20 miles). Emergency medical services arrival was associated with 23% shorter total ischemic times than self-arrival. CONCLUSIONS: Transfer patients from referral hospitals had significantly greater total ischemic time, and use of EMS was associated with significantly lower times. Transport distance was mixed in its effect. These findings suggest a continued focus on improving transitions between referral and receiving centers and enhancing coordination in rural systems of care to reduce the multiplier effect of transfers on total ischemic time.

Emergency medical services as a strategy for improving ST-elevation myocardial infarction system treatment times.

BACKGROUND: Reducing delays in time to treatment is a key goal of ST-elevation myocardial infarction (STEMI) emergency care. Emergency medical services (EMS) are a critical component of the STEMI chain of survival. STUDY OBJECTIVE: We sought to assess the impact of the careful integration of EMS as a strategy for improving systemic treatment times for STEMI. METHODS: We conducted a study of all 747 nontransfer STEMI patients who underwent primary percutaneous coronary intervention (PCI) in Dallas County, Texas from October 1, 2010 through December 31, 2011. EMS leaders from 24 agencies and 15 major PCI receiving hospitals collected and shared common, de-identified patient data. We used 15 months of data to develop a generalized linear regression to assess the impact of EMS on two treatment metrics-hospital door to balloon (D2B) time, and symptom onset to arterial reperfusion (SOAR) time, a new metric we developed to assess total treatment times. RESULTS: We found statistically significant reductions in median D2B (11.1-min reduction) and SOAR (63.5-min reduction) treatment times when EMS transported patients to the receiving facility, compared to self-transport. In addition, when trained EMS paramedics field-activated the cardiac catheterization laboratory using predefined specified protocols, D2B times were reduced by 38% (43 min) after controlling for confounding variables, and field activation was associated with a 21.9% reduction (73 min) in the mean SOAR time (both with p < 0.001). CONCLUSION: Active EMS engagement in STEMI treatment was associated with significantly lower D2B and total coronary reperfusion times.

Developing an ST-elevation myocardial infarction system of care in Dallas County.

BACKGROUND: The American Heart Association Caruth Initiative (AHACI) is a multiyear project to increase the speed of coronary reperfusion and create an integrated system of care for patients with ST-elevation myocardial infarction (STEMI) in Dallas County, TX. The purpose of this study was to determine if the AHACI improved key performance metrics, that is, door-to-balloon (D2B) and symptom-onset-to-balloon times, for nontransfer patients with STEMI. METHODS: Hospital patient data were obtained through the National Cardiovascular Data Registry Action Registry-Get With The Guidelines, and prehospital data came from emergency medical services (EMS) agencies through their electronic Patient Care Record systems. Initial D2B and symptom-onset-to-balloon times for nontransfer primary percutaneous coronary intervention (PCI) STEMI care were explored using descriptive statistics, generalized linear models, and logistic regression. RESULTS: Data were collected by 15 PCI-capable Dallas hospitals and 24 EMS agencies. In the first 18 months, there were 3,853 cases of myocardial infarction, of which 926 (24%) were nontransfer patients with STEMI undergoing primary PCI. D2B time decreased significantly (P < .001), from a median time of 74 to 64 minutes. Symptom-onset-to-balloon time decreased significantly (P < .001), from a median time of 195 to 162 minutes. CONCLUSION: The AHACI has improved the system of STEMI care for one of the largest counties in the United States, and it demonstrates the benefits of integrating EMS and hospital data, implementing standardized training and protocols, and providing benchmarking data to hospitals and EMS agencies.

A randomized controlled trial of a controlled breathing protocol on heart rate variability following myocardial infarction or coronary artery bypass graft surgery.

OBJECTIVES: To determine whether a controlled breathing programme increases heart rate variability following an acute myocardial infarction and/or coronary artery bypass graft surgery. RATIONALE: Heart rate variability is reduced following a myocardial infarction, and low heart rate variability is associated with a high mortality risk. By changing tidal volume and rate of breathing, individuals can alter beat-to-beat heart rate variability. It is hypothesized that heart rate increases with inspiration and decreases with exhalation, and that deep slow breathing enhances respiratory sinus arrhythmia, increasing heart rate variability. DESIGN: Randomized controlled trial. SETTING: Cardiac rehabilitation programme at a large academic medical centre in North Texas. SUBJECTS: From 2001 to 2005, 44 patients, age 46-65 years, who had a myocardial infarction and/or undergone coronary artery bypass graft surgery 1-8 weeks previously and were referred to the Cardiac Rehabilitation Program. INTERVENTION: Patients were randomized to either usual cardiac rehabilitation or cardiac rehabilitation with controlled breathing (6 breaths/min for 10 minutes twice daily during the eight-week treatment period). MAIN MEASURES: Weekly measurements of total power and standard deviation of the mean normal to normal RR interval (SDNN), and fortnightly measurements of respiratory sinus arrhythmia were taken using Biocom Technologies Heart Rhythm Scanner and Tracker software. RESULTS: No significant difference in change were seen between groups in SDNN (P = 0.3984), baseline respiratory sinus arrhythmia (P = 0.6556) or total power (P = 0.6184). CONCLUSION: Results suggest participation in the controlled breathing programme offered no additional benefit in increasing heart rate variability following myocardial infarction or coronary artery bypass graft surgery. However, 77% of study patients were on heart rate-lowering medications, which may have masked changes in heart rate variability.

Risk factor outcome comparison between exercise-based cardiac rehabilitation, traditional care, and an educational workshop.

BACKGROUND: This study examined risk factor outcomes among patients who attended cardiac rehabilitation sessions, those who received traditional care, and those who attended Leap for Life workshops. METHODS: A non-equivalent, three-group design was used in this observational study. Baseline and 12-month measurements were collected for 217 participants. Analysis of covariance was performed to determine differences between groups on outcome variables. RESULTS: The only significant finding was in participants with an initial high-density lipoprotein value of less than 40. High-density lipoprotein levels increased more in the cardiac rehabilitation group than in the traditional care group (30.54 to 37.48 versus 30.17 to 33.67 [F= 4.577, p = .035]). CONCLUSIONS: Based on these findings, a strong case can be made for the transition to more individually intense and focused risk factor modification strategies for patients in cardiac rehabilitation programs.

Interorganizational Collaboration in Emergency Cardiovascular Care.

BACKGROUND: Interorganizational collaboration management theory contends that cooperation between distinct but related organizations can yield innovation and competitive advantage to the participating organization. Yet, it is unclear if a multi-institutional collaborative can improve quality outcomes across communities. METHODS: We developed a large regional collaborative network of 15 hospitals and 24 emergency medical service agencies surrounding Dallas, Texas, and collected patient-level data on treatment times for acute myocardial infarctions. Using a pre-/posttest research design, we applied median tests of differences to explore outcome changes between groups and over the 6-year period, using data extracted from participating hospital electronic health records. RESULTS: We analyzed temporal trends and changes in treatment times for 2302 patients with ST-elevation myocardial infarction between the pre- and posttest groups. We found a statistically significant 19-minute median reduction in the key outcome metric (total ischemic time, the time difference between the patient's first reported symptoms and the definitive opening of the artery). This represents a 10.8% community-wide improvement over time. CONCLUSIONS: Interorganizational collaboration focused on quality improvement can impact population health across a community. This study provides a basis for broader understanding and participation by health care organizations in multi-institutional community change efforts.

Impact of a Rural Regional Myocardial Infarction System of Care in Wyoming.

BACKGROUND: Primary percutaneous coronary intervention (PCI) is the preferred reperfusion strategy for patients presenting with ST-segment elevation myocardial infarction; however, to be effective, PCI must be performed in a timely manner. Rural regions are at a severe disadvantage, given the relatively sparse number of PCI hospitals and long transport times. METHODS AND RESULTS: We developed a standardized treatment and transfer protocol for ST-segment elevation myocardial infarction in the rural state of Wyoming. The study design compared the time-to-treatment outcomes during the pre- and postintervention periods. Details of the program, changes in reperfusion strategies over time, and outcome improvements in treatment times were reported. From January 1, 2013, to December 31, 2014, 889 patients were treated in 11 PCI-capable hospitals (4 in Wyoming, 7 in adjoining states). Given the large geographic distance in the state (median of 47 miles between patient and PCI center), 52% of all patients were transfers, and 36% were administered fibrinolysis at the referral facility. Following the intervention, there was a significant shift toward greater use of primary PCI as the dominant reperfusion strategy (from 47% to 60%, P=0.002), and the median total ischemic time from symptom onset to arterial reperfusion was decreased by 92 minutes (P<0.001). There was a similar significant reduction in median time from receiving center door to balloon of 11 minutes less than the baseline time (P<0.01). CONCLUSIONS: Rural systems of care for ST-segment elevation myocardial infarction require increased levels of cooperation between emergency medical services agencies and hospitals. This study confirms that total ischemic times can be reduced through a coordinated rural statewide initiative.

Reassessing After-Hour Arrival Patterns and Outcomes in ST-Elevation Myocardial Infarction.

INTRODUCTION: Differences in after-hours capability or performance of ST-elevation myocardial infarction (STEMI) centers has the potential to impact outcomes of patients presenting outside of regular hours. METHODS: Using a prospective observational study, we analyzed all 1,247 non-transfer STEMI patients treated in 15 percutaneous coronary intervention (PCI) facilities in Dallas, Texas, during a 24-month period (2010-2012). Controlling for confounding factors through a variety of statistical techniques, we explored differences in door-to-balloon (D2B) and in-hospital mortality for those presenting on weekends vs. weekdays and business vs. after hours. RESULTS: Patients who arrived at the hospital on weekends had larger D2B times compared to weekdays (75 vs. 65 minutes; KW=48.9; p<0.001). Patients who arrived after-hours had median D2B times >16 minutes longer than those who arrived during business hours and a higher likelihood of mortality (OR 2.23, CI [1.15-4.32], p<0.05). CONCLUSION: Weekends and after-hour PCI coverage is still associated with adverse D2B outcomes and in-hospital mortality, even in major urban settings. Disparities remain in after-hour STEMI treatment.

Growth in percutaneous coronary intervention capacity relative to population and disease prevalence.

BACKGROUND: The access to and growth of percutaneous coronary intervention (PCI) has not been fully explored with regard to geographic equity and need. Economic factors and timely access to primary PCI provide the impetus for growth in PCI centers, and this is balanced by volume standards and the benefits of regionalized care. METHODS AND RESULTS: Geospatial and statistical analyses were used to model capacity, growth, and access of PCI hospitals relative to population density and myocardial infarction (MI) prevalence at the state level. Longitudinal data were obtained for 2003-2011 from the American Hospital Association, the U.S. Census, and the Centers for Disease Control and Prevention (CDC) with geographical modeling to map PCI locations. The number of PCI centers has grown 21.2% over the last 8 years, with 39% of all hospitals having interventional cardiology capabilities. During the same time, the US population has grown 8.3%, from 217 million to 235 million, and MI prevalence rates have decreased from 4.0% to 3.7%. The most densely concentrated states have a ratio of 8.1 to 12.1 PCI facilities per million of population with significant variability in both MI prevalence and average distance between PCI facilities. CONCLUSIONS: Over the last decade, the growth rate for PCI centers is 1.5× that of the population growth, while MI prevalence is decreasing. This has created geographic imbalances and access barriers with excess PCI centers relative to need in some regions and inadequate access in others.